Triggered fastener driving tool for two-step operation



P. D. BECKER 2,582,578

TRIGGERED FASTENER DRIVING TOOL FOR TWO-STEP OPERATION Jan. 15, 1952 Filed March '7, 1950 Fl G.

m mwlm 4 \Nv NTQR: Pump D. BECKER,

ATTORNEY.

Patented Jan. 15, 1952 TRIGGERED FASTENER DRIVING TOOL FOR TWO-STEP OPERATION Philip D. Becker, Hingham, Mass., assignor to United Carr Fastener Corporation, Cambridge, Mass., a corporation of Massachusetts Application March 7, 1950, Serial No. 148,143

4 Claims.

This invention relates generally to driving tools for fasteners and the like, and has particular reference to a tool for use in driving-into a supporting member of wood or the like a fastener which comprises a flanged nut and a pronged sleeve disposed about the barrel of the nut for engagement with the supporting member.

The object of the invention is to provide a tool for driving fasteners of the type described above in which an outer punch and an inner punch having annular punch surfaces are capable of controlled longitudinal movement relative to one another during driving of the fastener.

A further object of the invention is to provide a tool as described above in which an outer punch for engagement with the sleeve of a fastener and an inner punch for engagement with the nut of a fastener are disposed for controlled independent movement during driving of a fastener to enable the sleeve to be driven into engagement with a supporting member after the nut is seated thereagainst.

A still further object of the invention is to provide a driving tool in which a trigger member is utilized to carry the fastener into position for driving and also to release driving pressure from a portion of the fastener at a predetermined point in the driving operation.

Other objects of the invention will, in part, be

obvious, and will, in part, appear hereinafter. 1::

into a supporting member;

Fig. 3 is a view in elevation, partly in section, similar to Fig. 2, in which the punch has moved downwardly through a portion of its stroke, illustrating the action of the trigger rod in operating inner punch release mechanism, and showing the tool attached to an element of a machine for applying pressure to the tool;

Fig. 4 is a view similar to Fig. 3 in which the punch has reached the downward limit of its stroke, illustrating the action of the component parts of the punch in driving the sleeve member of the fastener into engagement with the supporting member;

Fig. 5 is a bottom plan view of the driving tool I of Fig. 1;

.tures and advantages of the driving tool.

Fig. 6 is a perspective of a fastener member for use with the tool of the invention with a portion thereof, brokenaway.

Referring to the drawing, there is illustrated a driving tool is, which is adapted'for driving fasteners l2 into a supporting member 14 of wood or the like.

The fasteners I2 for use with the tool form no part of the present invention, but an understanding of their construction and method of application is essential to an understanding of the fea- Generally the fasteners l2 comprise a nut i6, having a shank It, a flange 20 disposed on one end of the shank, and a threaded bore 22 disposed therethrough to receive a bolt, (not shown) and a sleeve 24 disposed about the shank. The sleeve 24, prior .to engagement with the supporting memher, is provided with prongs 26 on one end which rest against the flange 2c of the nut. The assembly operation requires that the flange 20 of the nut, be seated against the bottom of an opening 28 in the supporting member, and that sufficient pressure then be exerted against the sleeve to curl the prongs 26 outwardly on the flange 20 and I into the wall of the opening, as illustrated in Fig. i, to lock the fastener into place. During the assembly it is essential that the flange 20 be firmly seated against the bottom of the opening before the prongs 26 are curled outwardly, to insure that the nut will be firmly retained against the bottom of the opening and to provide a solid backing for the curling action of the prongs 26.

To accomplish the above results, the tool It] is constructed so as to impart an initial driving force to both the sleeve and the nut to seat the nut firmly against the bottom of the opening, after which mechanism in the tool I0 which is actuated by the seating of the nut operates to release the driving force from the .nutand apply such force only to the sleeve to accomplish the outward curlingof the prongs 26.

opening 36 and an annular punch surface 38 Y which is adapted to engage the end of the shank of the nut. A trigger rod 48 is disposed in the central opening 36 and extends from the lower end thereof to form a fastener receiving portion 42,

which may be provided with a spring 43' for frictional engagement in the bore 22 of the nut when the fastener is mounted thereon.

The inner punch 34 is provided with a flange portion 44, which normally seats against an interior shoulder 45 in the outer punch so that the outer and inner punch surfaces are properly positioned for the driving operation. The outer punch 3!! is provided with a series of longitudinal slots 46 which terminate at the lower end substantially opposite the upper side of the flange 44 of the inner punch. Disposed in each slot 46 is arocker arm 48, which has a lower end 50 which is capable of radial movement inward and outward in its slot, and an upper end 52 about which the lower end pivots. To retain the upper ends 52 of the rocker arms in position a cap member 54 is assembled on the top of the outer punch, and has a depending skirt 56 which surrounds the punch and covers the upper portion of the slots 46. A recess 58 is provided on the inner edge of each rocker arm, which forms a camming surface 60 for a purpose to be hereinafter described.

The interior of the inner punch 34 is provided with 'an annular shoulder 62, and the trigger rod 40 is provided with a flange 64 which normally seats thereagainst to determine the extent of protrusion thereof from the front end of the inner sleeve. lower end disposed in the central opening 36, and an upper end disposed in an opening 68 in the cap member 54, is assembled centrally of the rocker arms 48, and is provided with a circular cam Til which is normally disposed in the recesses 58 in the rocker arms. The trigger extension 66 and the trigger rod 40 are biased downwardly by a spring '12 which surrounds the trigger extension and seats against the cam 19 at the lower end;

'74 which is mounted about the outside of the rocker arms, and when in this position, the lower ends of the rocker arms protrude far enough through the slots 46 to cover a portion of the flange 44 on the inner punch and lock it in the downward position as illustrated in Fig. 2.

The method of assembly of a fastener I2 into the opening 28 in the supporting member I4 is illustrated in Figs. 2-4. The fastener I2 is placed on the fastener receiving portion 42 on the end of the trigger rod 48 so that the end of the shank I8 of the nut and the upper end of the sleeve 24 are in position to bear against the punch surfaces 38 and 32 respectively. The length of the fastener receiving portion 42 of the trigger rod 48 is such that when the fastener I2 is assembled thereon, the trigger rod protrudes therefrom a predetermined distance for a purpose to be hereinafter described. The spring 43 is compressed slightly when the fastener is mounted thereon and frictionally engages the internal threaded bore 22 of the nut to retain the fastener thereon. The tool it is then positioned over the opening, and forced downwardly so that the fastener I 2 enters the opening and the end of the trigger rod 49 protruding from the fastener contacts the bottom of the opening as illustrated in Fig. 2. As the tool Ill continues to move downwardly, the fastener I2 is forced further into the opening, and since the trigger rod 40 and the trigger rod extension 56 cannot move further downwardly, the camming surfaces 60 on the rocker arms 48 ride over the cam 16 on the trigger extension, thereby forcing the lower ends 50 of the rocker arms outwardly, as illustrated in Fig. 3. The dimensions of the fastener and the tool component parts of the tool are so arranged that at ubstantially the moment that the flange of A'trigger rod extension 68, which has a the nut of the fastener is seated against the bottom of theopening, the camming action above described has caused the lower ends 59 of the rocker armsto move completely off the flange 44 on the inner punch 34. When this occurs, the downward force on the inner punch 34, and consequently on the nut I6, is released, since downward forces are imparted thereto only by the rocket arms 48. This action has just occurred in the position of the punch illustrated in Fig. 3. Further downward force applied to the tool is consequently transmitted only to the outer punch surface 32, to drive the sleeve 24 downwardly relative to the nut. During such downward movement of the sleeve, the flange 22 of the nut provides a die surface to turn the prongs 28 of the sleeve outwardly to pierce the material of the supporting member immediately above the flange 20, thereby locking the'nut securely in the opening 28 against the bottom thereof.

The tool ll! may then be removed from the opening, which pulls the trigger rod out of the fastener, which is then ready to receive a bolt (not shown) to fasten an article to the supporting member. The spring 12 returns the trigger rod 40 and trigger rod extension 66 to the normal position, and the spring 14 returns the rocket arms into the slots to again seat on the flange 44 of the inner punch to prepare the tool for another fastener driving operation.

Although the operation of the device has been described as though the action occurs in distinct steps, it will be evident that in driving a fastener, the driving force is applied by a continuous downward movement.

Since certain obvious modifications may be made in the device without departing from the scope of the invention, it is intended that all matter contained herein be interpreted in an illustrative and not in a limiting sense.

I claim:

1. Adriving tool for fasteners, comprising a hollow outer punch, an inner punch disposed therein for longitudinal movement relative to the outer punch, said inner punch having a 1ongitudinal central opening, a trigger rod disposed in the central opening for longitudinal movement therein relative to the inner punch, said trigger rod normally extending a predetermined distance outwardly from the punch surface of said inner punch to receive a fastener device thereon, releasable means associated with the outer punch and the inner punch for transmn ting downward forces from the outer punch to the inner punch, and means operated by said trigger rod upon a predetermined upward movementof the trigger rod relative to the inner punch for releasing said releasable means so that after .said predetermined upward movement of the trigger rod no downward forces are transmitted from the outer punch to the inner punch.

2. A driving tool for fasteners of the type comprising a flanged nut and a pronged sleeve disposedabout the nut for engagement with a supporting member, said tool comprising a hollow outer punch having an annular punch surface for engagement with the end of the sleeve of a fastener, an inner punch disposed therein for longitudinal movement relative to the outer punch, said inner punch having a longitudinal central opening and an annular punch surface forengagement with the end of the nut of the fastener, a trigger rod disposed in the central opening for longitudinal movement therein relative' to the inner punch, said trigger rodnormally extending a predetermined distance outwardly from the punch surface of the inner punch to receive a fastener device thereon, and having means thereon for frictionally engaging the nut 01 the fastener, releasable means disposed between a portion of the outer punch and the upper end of the inner punch for transmitting downward forces from t-e outer punch to the inner punch, and cam means operated by said trigger rod upon a predetermined upward movement of the trigger rod relative to the inner punch for releasing said releasable means, whereby during driving of a fastener, downward forces are applied by the inner punch to the nut until completion of said predetermined upward movement of the trigger rod, after which downward forces are applied only to the sleeve member.

3. A driving tool for fasteners, comprising a hollow outer punch, an inner punch disposed therein for longitudinal movement relative to the outer punch, said inner punch having a longitudinal central opening, a trigger rod disposed in the central opening for longitudinal movement therein relative to the inner punch, said trigger rod normally extending a predetermined distance outwardly from the punch surface of the inner punch to receive a fastener device thereon, a series of rocker arms disposed about the outer punch, each of said rocker arms having an upper end disposed to receive downward forces from the outer punch, a lower end normally seated against a portion of the inner punch to transmit downward punch forces thereto, and a cam surface on the inner ed e thereof, cam

means disposed between the cam surfaces of the rocker arms, said cam means being operable by said trigger rod upon upward movement of the trigger rod relative to the inner punch to move the lower ends of the rocker arms outwardly out of engagement with the inner punch so that no downward forces are transmitted from the outer punch to the inner punch.

4. A driving tool for fasteners of the type comprising a flanged nut and a pronged sleeve disposed about the nut for engagement with a supporting member, said tool comprising a hollow outer punch having an annular punch surface for engagement with the end of the sleeve of a fastener, an inner punch disposed therein for longitudinal movement relative to the outer punch, said inner punch having a longitudinal central opening and an annular punch surface for engagement with the nut of a fastener, a trigger rod disposed in the central opening for longitudinal movement therein relative to the inner punch, said trigger rod normally extending a predetermined distance outwardly from the punch surface of the inner punch to receive a fastener device, and having spring means thereon for entering the bore of the nut of the fastener for frictional engagement therewith, a trigger rod extension disposed in said hollow outer punch, said trigger rod extension having an annular cam disposed for longitudinal movement therein in response to upward movement of the trigger member relative to the inner punch, a series of rocker arms disposed about the cam, said rocker arms having upper ends adapted to receive downward forces from the outer punch, lower ends normally seated against a portion of the inner punch to transmit downward forces thereto, and cam surfaces disposed for engagement with the cam on the trigger rod extension in response to upward movement thereof to move the lower ends of the rocker arms outwardly out of engagement with the inner punch, whereby during driving of a fastener, downward forces are applied by the inner punch to the nut until said upward movement of the trigger member, after which downward forces are applied only to the sleeve member.

PHILIP D. BECKER.

No references cited. 

